最短時間でのタンパク質 NMR ダイナミクスの極度の非均一なサンプリング
Gregory Jameson1,2, Alexandar L Hansen3, Dawei Li3
1Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States.
Journal of the American Chemical Society
|September 28, 2019
まとめ
この研究では,最適化された非均一なサンプリング (NUS) を使用した15N化学交換飽和移転 (CEST) NMR実験を加速するための新しい方法が導入されています. このアプローチは,タンパク質のダイナミクスの測定を大幅に加速し,人工物を最小限にします.
科学分野:
- 核磁共振 (NMR) スペクトロスコーピー
- タンパク質ダイナミクス
- 生物物理化学
背景:
- NMRスペクトロシピは,スピンリラクゼーションまたは化学交換飽和移転 (CEST) を通じてタンパク質のダイナミクスの定量的な洞察を提供します.
- 標準の15N-CEST測定は,長時間の擬似3DHSQC実験のために時間がかかります.
- 非均一なサンプリング (NUS) はこれらの実験を加速させることができるが,多くの場合,最適化が課題として残る.
研究 の 目的:
- 15N-CEST実験のためのNUSスケジュールを最適化するための体系的なアプローチを開発し,検証する.
- 定量的な多次元 NMR 試験の測定時間を大幅に短縮する.
- 加速されたNMRデータ取得に関連したアーティファクトを最小限に抑える.
主な方法:
- 2D HSQCの基準実験から取り付けられたクロスピークを"足跡"として使って,CESTの擬似3Dデータを再構築した.
- ラジオ周波数オフセット (Δω) の関数として交差ピークの振幅を決定する線形最小平方フィッティングを使用します.
- Cramer-Rao下限メトリックに基づくスペクトル固有の最適化非均一サンプリング (SONUS) スキームを実施した.
主要な成果:
- タンパク質Im7の非常に正確なCESTプロフィールを取得する20〜30倍の速度を達成しました.
- 基準実験のクロスピークを使用してアンダーサンプリングデータを再構築する効果が実証されました.
- SONUSによる最適なサンプリングスケジュールの一般的な性質を特定した.
結論:
- 開発された方法は,定量的な多次元 NMR 測定の劇的な加速を可能にします.
- 15N-CESTのためのNUSスケジュールのこのシステマティックな最適化は,エラーとアーティファクトを最小限にします.
- この発見は,溶液中のタンパク質の動態に関するより効率的な研究への道を開きます.
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